Preparation Technology And Application Of High Dietary Fiber Tofu

Soybean has a long history of cultivation and consumption in China,and it is rich in protein,lipids,and dietary fiber.In recent years,with the elucidation of many physiologically active components of soybeans,foods with soybeans as basic raw materials have been universally favored worldwide.There are a variety of soybean products.As a healthy food material with high nutritional value,the consumption of soybean has always been large.Tofu is a traditional soybean product in China.It contains most of the nutrients of soybeans and has a good taste,so it is widely loved by the Chinese people.However,the production of tofu is accompanied by a large amount of soybean dregs,which contains a large amount of soybean dietary fiber.Soy dietary fiber has better health-promoting functions,but its poor texture quality makes it costly to be used in production and is eventually abandoned.Countless soybean dietary fiber was discarded in the tofu production process.This is a serious problem that has not been effectively solved.In order to improve the application level of soybeans and improve the application status of soybean dietary fiber,this research takes soybeans as the object and applies ultrafine grinding-high pressure homogenization technology to prepare high dietary fiber drinks and tofu.It also aims at extracting and modifying soybean protein for further application.The content and results of this research are as follows:1.The high-dietary fiber soy milk is prepared by the wet superfine pulverization-high-pressure homogenization method.First,the soy milk is prepared by the wet superfine pulverization method and passed through a 60-mesh sieve,and the obtained soy milk is subjected to high-pressure homogenization treatment.The particle size and non-covalent effects of soy milk,the content and crystal structure of dietary fiber,the degree of protein denaturation,and the sensory quality of soy milk were studied.The results showed that high-pressure homogenization effectively reduced the particle size of bean dregs and improved the sensory quality of high dietary fiber soy milk,but did not have a significant impact on the structure of protein and dietary fiber.2.Preparation of high dietary fiber tofu.Gypsum and gluconolactone(GDL)are used as coagulants,and soybean milk in 1 is used to prepare high dietary fiber tofu.The yield,moisture content,rheological properties,microstructure and sensory quality of high dietary fiber tofu were studied.The results showed that tofu with GDL as coagulant(G120,G0,G1,G2,G3)had good texture and sensory quality,and there was no significant difference between them.There were significant differences in the texture and sensory quality of tofu with gypsum as coagulant.High dietary fiber tofu(C0)that had not been homogenized by high pressure had poor texture and sensory quality.High dietary fiber tofu(C1,C2,C3)that had been homogenized by high pressure had better structure,and the sensory quality was not significantly different from each other.3.Modification and application research of soy protein isolate(SPI).To prepare olive oil as the oil phase food-grade emulsion,SPI is extracted from soybean seed meal.Then,SPI and pectin are prepared into SPI-pectin composite nanoparticles(SPNPs),and hydroxypropyl methylcellulose(HPMC)are compounded as emulsifier.The non-covalent effect,surface charge,and interface properties of SPNPs-HPMC system as well as the microstructure,mechanical properties,dynamic interfacial tension,and lipolysis efficiency of the emulsion with SPNPs-HPMC system as a stabilizer were characterized.The results showed that during the formation and stabilization of the emulsion,HPMC and SPNPs were co-adsorbed on the interface of an emulsion sample with a HPMC concentration of 0.25-0.5wt%.HPMC and SPNPs competed to adsorb on the interface at a HPMC concentration of 1-2wt % Of the emulsion samples.Among them,HPMC had an advantage.The interface of HPMC molecules was adsorbed in the early stage of emulsion formation.HPMC molecules controlled the distribution and surface area of emulsion droplets,but they had a poor ability to stabilize emulsion droplets.Rearranging after HPMC molecules,the SPNPs particle's interface adsorption had a strong ability to stabilize emulsified droplets.Under the conditions of simulating stomach and intestine in vitro,SPNPs were decomposed into substances with lower interfacial activity.The structure and activity of HPMC were better maintained.During the lipolysis process,an interface dominated by HPMC was formed.The aggregation of emulsion oil droplets and the undecomposed SPNPs formed a new interface layer,so that the size distribution and surface area of the emulsion droplets were better maintained for the lipid breakdown process.